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Analysis of Heat Transfer and Optimum Structural Design for Cooling Channel of Supersonic Nozzle
Takeshi Kagawa,Tomohiro Niimura,Katsumi Hiraoka 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
The purpose of this study is optimum structural design for cooling channel of supersonic nozzle for rockets. Nowadays. there are two types of structure of cooling system for supersonic nozzle. One is using cooling pipe around the supersonic nozzle for cooling. The other is making cooling channel around the supersonic nozzle for cooling. Later case does not need brazing. And the advantage of later case is using copper of cooling channel. Copper has high coefficient of thermal conductivity. Later case is able to be made by cast. So, production run for cooling system of supersonic nozzle is shorter than that for the former case. Although reliability of the later case is higher than that for the former case, because of no brazing, mass of the later case is heavier than that of the former case. Then, it is needed that mass of the later case will be reduced with optimum structural design. We chose the later case and do optimum structural design by using two softwares, fluid analysis software FLUENT and structure analysis software NASTRAN. The rockets are able to load more payloads by optimum structural design. Thereby we are able to decrease per unit weight cost to lunch rockets.
Investigation of the Downwash Induced by Rotary Wings in Ground Effect
Yasutada Tanabe,Shigeru Saito,Naoko Ooyama,Katsumi Hiraoka 한국항공우주학회 2009 International Journal of Aeronautical and Space Sc Vol.10 No.1
There are concerns about the influence of the gust wind caused by helicopters affecting the moving vehicles while hovering over the road during rescue activities. For the understanding of such complicated flow, numerical simulation of a rotor hovering above the ground has been carried out, changing the rotor/ground clearances. The rotor thrust is kept constant, and the rotor control is determined by trim adjustments incorporated into the CFD algorithm. Collective pitch angle and the required power decreases with the rotor/ground clearance which agrees with experience. Changes of the flowfield near the rotor with regard to the rotor height are investigated based on the calculated results.
Investigation of the Downwash Induced by Rotary Wings in Ground Effect
Yasutada Tanabe,Shigeru Saito,Naoko Ooyama,Katsumi Hiraoka 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
There is concerns about the influence of the gust wind caused by helicopter affecting on the moving vehicles while the helicopter hovering over the road during the rescue activity. For the understanding of such complicated flow, numerical simulation of a rotor hovering above the ground has been carried out by changing the rotor/ground clearances. The rotor thrust is kept constant, and the rotor control is determined by trim adjustments incorporated into the CFD algorithm. Collective pitch angle and the required power decreases with the rotor/ground clearance which agrees with the experiences. Changes of the flow field near the rotor with regard to the rotor height are investigated based on the calculated results.
Investigation of the Downwash Induced by Rotary Wings in Ground Effect
Tanabe, Yasutada,Saito, Shigeru,Ooyama, Naoko,Hiraoka, Katsumi The Korean Society for Aeronautical and Space Scie 2009 International Journal of Aeronautical and Space Sc Vol.10 No.1
There are concerns about the influence of the gust wind caused by helicopters affecting the moving vehicles while hovering over the road during rescue activities. For the understanding of such complicated flow. numerical simulation of a rotor hovering above the ground has been carried out, changing the rotor/ground clearances. The rotor thrust is kept constant. and the rotor control is determined by trim adjustments incorporated into the CFD algorithm. Collective pitch angle and the required power decreases with the rotor/ground clearance which agrees with experience. Changes of the flowfield near the rotor with regard to the rotor height are investigated based on the calculated results.